Fix checksum offload sssue caused by overwriten lX_hdr_offset

This happens when 2 packets belonging to 2 different interfaces hit
dual loop in the ethernet-input. Packets go to slow path which doesn't
set l2 hdr offset correctly for l3 packets.

Change-Id: I61d87c079db0b2e21f8af6f6b600bff14030535d
Signed-off-by: Damjan Marion <damarion@cisco.com>

diff --git a/src/vnet/ethernet/node.c b/src/vnet/ethernet/node.c
index 3760877..a2e7524 100755 (executable)
--- a/src/vnet/ethernet/node.c
+++ b/src/vnet/ethernet/node.c
@@ -229,6 +229,8 @@ determine_next_node (ethernet_main_t * em,
                     u32 is_l20,
                     u32 type0, vlib_buffer_t * b0, u8 * error0, u8 * next0)
 {
+  u32 eth_start = vnet_buffer (b0)->l2_hdr_offset;
+  vnet_buffer (b0)->l2.l2_len = b0->current_data - eth_start;
   if (PREDICT_FALSE (*error0 != ETHERNET_ERROR_NONE))
     {
       // some error occurred
@@ -238,8 +240,6 @@ determine_next_node (ethernet_main_t * em,
     {
       *next0 = em->l2_next;
       // record the L2 len and reset the buffer so the L2 header is preserved
-      u32 eth_start = vnet_buffer (b0)->l2_hdr_offset;
-      vnet_buffer (b0)->l2.l2_len = b0->current_data - eth_start;
       ASSERT (vnet_buffer (b0)->l2.l2_len ==
              ethernet_buffer_header_size (b0));
       vlib_buffer_advance (b0, -ethernet_buffer_header_size (b0));